To Determine the Time of Onset of Visual Symptoms, Clinical Visualization of Posterior Capsular Opacification and Median Survival Prior to Yag Capsulotomy With Staar Collamer Lenses Using Hydrophobic Acrylic Lenses as Control

Abstract

 

Purpose:

 

To determine time of onset of visual symptoms, visualization of posterior capsular opacification and median survival prior to YAG capsulotomy associated with the unique fibrous thickening of the posterior capsule after STAAR Collamer (collagen co–polymer) lens implantation, using hydrophobic Acrylic lenses as control

 

Methods:

 

The charts of 217 patients (248 eyes) who underwent Nd:YAG capsulotomy for a Posterior Capsular Opacity between Sep 1999 and Feb 2005 were reviewed retrospectively. Dates of presentation with symptoms of decreased visual acuity on account of PCO, the first clinical sign of a posterior capsular opacification regardless of symptoms and that of Nd:YAG capsulotomy were noted. Time to these events after cataract surgery was evaluated using Kaplan–Meier survival analysis and the equality of survival distributions were tested using the Log Rank (Mantel–Cox) test

 

Results:

 

Patients with Acrylic lenses tend to be symptomatic earlier (306 days) than those with Collamer (405 days), although this did not reach statistical significance; p=0.080. There was no difference in mean survival after cataract surgery to when PCO was first noted clinically between Acrylic (259 days) and Collamer (294 days) p=0.561. There was further no difference in mean survival prior to YAG capsulotomy between the two lenses (Acrylic 454 days; Collamer 541 days) p=0.342

 

Conclusions:

 

Although eyes implanted with the Collamer Lenses led to the majority (46%) of capsulotomies in this population and formed a unique fibrotic thickening of the posterior capsule as opposed to typical posterior capsular opacification seen with Lens Epithelial Cell migration with Acrylic, our study showed that there was no difference in mean survival after cataract surgery prior to noting PCO, onset of clinical symptoms or to YAG capsulotomy between the two. We conclude that although the mechanism of PCO formation with Collamer lenses might be different from that seen with Acrylic lenses, this does not translate to early symptoms or interventions.  

 

Keywords: anterior segment • intraocular lens • posterior capsular opacification (PCO)